Water detection systems are well known and have been in use for over 25 years. For example a U.S. patent of Barron, U.S. Pat. No. 4,987,408 discloses water sensor unit wherein a plurality of water related appliances or equipment can be simultaneously monitored and in the event of sensing water with respect to any one of the several items being monitored appropriate action is taken such as shutting off the power to the unit and simultaneously shutting off the water supply to that particularly unit. The sensor unit comprises a plurality of electronic circuits which include a “memory” permitting retention of a ground fault even through a power failure for up to 500 hours.
Amore recent U.S. Pat. No. 5,188,143 of Krebs discloses a water leak detector that is sensitive to the presence of moisture, having an elongated sensor strip comprising a pair of conductors separated by insulation. Each conductor includes an electrode coupling with a wire lead extending via a cable to an electrical plug. A circuit housing, is provided having an audible alarm operably connected to an electrical socket adapted to detachably connect with the plug. A low voltage battery and auxiliary output socket are carried on the housing and connected with the alarm and the first mention socket whereby the presence of moisture across the pair of sensor conductors activates the alarm. A battery and test pair of electrodes are provided to manually test a battery condition.
In addition, an automatic flood prevention system is described in a U.S. Pat. No. 6,675,826 of Newman et al. As disclosed, a flood prevention system includes a double-latching solenoid valve that shuts off a water supply line in response to a moisture sensor detecting a leak in a plumbing system. The double-latching feature provides the solenoid's plunger with two positions of equilibrium. This minimizes electrical power consumption so that the flood prevention system can be battery operated. To minimize a buildup of hard water deposits, the valve includes a flexible diaphragm and is cycled periodically regardless of whether flooding occurs. The sensor includes multiple methods of mounting to a floor.
A HIVAR air conditioning unit is a recent development attributed to the manufacture of the Hiross range of comfort air conditioners. Such units use chilled water for cooling and hot water or electric coils for heating. The HIVAR units supply air into a floor void and take return air back through floor vents or with the addition of an extension hood draw air back through a false ceiling.
Notwithstanding the above it is presently believed that there is a need and a potential commercial market for an improved water detector. There should be a market for such detectors because they are adapted to operate in a main mode as for example a cooling mode and in a sub-mode or heating mode. In addition, the cost for such systems is relatively small, the units are relatively inexpensive and yet rugged and easy to install and/or replace.